Factor V Leiden (R506Q) Mutation, Blood
Use
This test is useful for identifying patients with clinically suspected thrombophilia, particularly those with activated protein C (APC) resistance, which may be proven or suspected by a low or borderline APC-resistance ratio, or a family history of factor V Leiden. It detects the F5 c.1601G>A; p.Arg534Gln variant, associated with APC resistance, which is prevalent in 12% to 20% of patients with venous thromboembolism.
Special Instructions
A previous bone marrow transplant from an allogenic donor may interfere with the testing. For testing such patients, it is advised to call the provided helpline for instructions. Informed consent is required for New York clients, and it must be documented that a copy is on file. The test is available for order in New York state.
Limitations
This assay will detect the genetic basis for APC resistance due to the F5 c.1601G>A, p.Arg534Gln variant, but not due to other genetic variants or acquired causes. Rare SNPs under the primers can result in preferential amplification causing inaccurate results. Discrepancies may occur between the DNA-based test and APC resistance assay in patients who have undergone allogenic transplants. Genetic counseling is advised before testing asymptomatic family members.
New York Approved
Methodology
PCR-based (RT-PCR)
Biomarkers
LOINC Codes
- 21668-9
- 21668-9
- 69049-5
- 18771-6
Result Turnaround Time
3-5 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
1 mL
Container
Lavender top (EDTA); also acceptable: Yellow top (ACD solution B), light-blue top (sodium citrate)
Collection Instructions
Invert several times to mix blood. Send specimen in original tube. Do not aliquot.
Patient Preparation
A previous bone marrow transplant from an allogenic donor will interfere with testing.
Causes for Rejection
Extracted DNA
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |